Add SPDX lines to each imported TinyCrypt file
Out of the 6 tinycrypt files included in Mbed TLS, this commit adds SPDX lines
to each for the BSD 3 Clause licence.
diff --git a/tinycrypt/ecc_dsa.c b/tinycrypt/ecc_dsa.c
index 3743091..c093ebe 100644
--- a/tinycrypt/ecc_dsa.c
+++ b/tinycrypt/ecc_dsa.c
@@ -3,6 +3,8 @@
/* Copyright (c) 2014, Kenneth MacKay
* All rights reserved.
*
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright notice,